Atmospheric size-resolved trace elements in a city affected by non-ferrous metal smelting: Indications of respiratory deposition and health risk.

This study examines size-resolved heavy metal data for particles sampled near an urban site affected by non-ferrous metal smelting in China with a focus on how particle sizes impact regional respiratory deposition behavior. Particles with aerodynamic diameters between 0.43 and 9 μm were collected during winter haze episodes from December 2011 to January 2012. The results showed that concentrations of individual trace elements ranged from ∼10(-2)-∼10(4) ng/m(3). Mass size distributions exhibit that Cu, Zn, As, Se, Ag, Cd, TI, and Pb have unimodal peak in fine particles range (<2.1 μm); Al, Ti, Fe, Sr, Cr, Co, Ni, Mo, and U have unimodal peak in coarse range (>2.1 μm), and Be, Na, Mg, Ca, Ba, Th, V, Mn, Sn, Sb, and K have bimodal profiles with a dominant peak in the fine range and a smaller peak in the coarse range. The total deposition fluxes of trace elements were estimated at 2.1 × 10(-2) - 4.1 × 10(3) ng/h by the MPPD model, and the region with the highest contribution was the head region (42% ± 13%), followed by the tracheobronchial region (11% ± 3%) and pulmonary region (6% ± 1%). The daily intake of individual element for humans occurs via three main exposure pathways: ingestion (2.3 × 10(-4) mg/kg/day), dermal contact (2.3 × 10(-5) mg/kg/day), and inhalation (9.0 × 10(-6) mg/kg/day). A further health risk assessment revealed that the risk values for humans were all above the guidelines of the hazard quotient (1) and cancer risk (10(-6)), indicating that there are potential non-cancer effects and cancer risks in this area.